Pain
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Randomized Controlled Trial
Observing treatment outcomes in other patients can elicit augmented placebo effects on pain treatment: a double-blinded randomized clinical trial with patients with chronic low back pain.
Clinical research on social observational learning (SoL) as an underlying mechanism for inducing expectancy and eliciting analgesic placebo effects is lacking. This double-blinded randomized controlled clinical trial investigated the influence of SoL on medication-augmenting placebo effects in 44 patients with chronic low back pain. Our hypothesis was that observing positive drug effects on pain and mobility in another patient could increase pain reduction and functional capacity. ⋯ After the intervention, pain decreased in both groups (F [1, 41] = 7.16, P < 0.05, d = 0.83), with no difference between groups. However, the SoLG showed a significantly larger decrease in perceived disability (F [1, 41] = 5, P < 0.05, d = 0.63). The direct observation of patient with chronic low back pain of positive treatment outcomes in the sham patient seems to have enhanced the treatment effects while indirect verbal reports of reduced pain did not.
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Meta Analysis
Potential role of blood biomarkers in patients with fibromyalgia: a systematic review with meta-analysis.
Fibromyalgia (FM) is a complex chronic pain condition. Its symptoms are nonspecific, and to date, no objective test exists to confirm FM diagnosis. Potential objective measures include the circulating levels of blood biomarkers. ⋯ Nevertheless, this systematic literature review and meta-analysis could not support the notion that these blood biomarkers are specific biomarkers of FM. Our literature review, however, revealed that these same individual biomarkers may have the potential role of identifying underlying pathologies or other conditions that often coexist with FM. Future research is needed to evaluate the potential clinical value for these biomarkers while controlling for the various confounding variables.
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Ivabradine, a hyperpolarization-activated cyclic nucleotide-gated cation (HCN) channel blocker and clinically approved bradycardic agent, has analgesic effects against neuropathic pain. Although the expression of HCN channels in the spinal dorsal horn (SDH) is augmented under inflammatory pain, spinal responses to centrally and peripherally applied ivabradine remain poorly understood. We investigated the spinal action and cellular mechanisms underlying the drug's analgesic effects against inflammatory pain using inflammatory pain model rats. ⋯ These phenomena were inhibited by forskolin, an activator of HCN channels. In conclusion, spinal responses mediated by HCN channels on primary afferent terminals are suppressed by central and peripheral administration of ivabradine; the drug also exhibits analgesic effects against inflammatory pain. In addition, ivabradine preferentially acts on C-fiber terminals of SDH neurons and induces a stronger inhibition of neuronal excitability in inflammatory pain.
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Randomized Controlled Trial
The Pain Course: a randomised controlled trial and economic evaluation of an internet-delivered pain management program.
There is interest in the potential of Internet-delivered programs to cost-effectively increase access to pain management for people with chronic pain. However, few large-scale clinical and economic evaluations have been undertaken. Using a randomised controlled trial design, the current study (n = 659) examined the clinical efficacy, cost-effectiveness, and cost utility of an Internet-delivered pain management program for people with mixed chronic pain conditions when delivered with optional clinician support. ⋯ The findings support the clinical efficacy and cost-effectiveness of Internet-delivered programs with "on demand" clinician support as a way to increase access to pain management. Key limitations of the current study include the use of a waitlist-control group, a short follow-up period, and the focus on governmental healthcare costs. Further evaluation of these programs is necessary if they are scaled up and offered as routine care.
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Randomized Controlled Trial
Transcranial direct current stimulation of three cortical targets is no more effective than placebo as treatment for fibromyalgia: a double-blind sham-controlled clinical trial.
Transcranial direct current stimulation (tDCS) over the primary motor cortex (M1) and the dorsolateral prefrontal cortex seem to improve pain and other symptoms of fibromyalgia (FM), although the evidence on the effectiveness of tDCS and the optimal stimulation target is not robust enough. Our main objective was to establish the optimal area of stimulation, comparing the 2 classical targets and a novel pain-related area, the operculo-insular cortex, in a sham-controlled trial. Using a double-blind design, we randomly assigned 130 women with FM to 4 treatment groups (M1, dorsolateral prefrontal cortex, operculo-insular cortex, and sham), each receiving fifteen 20-minute sessions of 2 mA anodal tDCS over the left hemisphere. ⋯ The linear mixed-model analysis of variances showed significant treatment effects across time for clinical pain and for fatigue, cognitive and sleep disturbances, and experimental pain, irrespective of the group. In mood, the 3 active tDCS groups showed a significantly larger improvement in anxiety and depression than sham. Our findings provide evidence of a placebo effect, support the use of tDCS for the treatment of affective symptoms, and challenge the effectiveness of tDCS as treatment of FM.